Variable speed circular saw - has belt driven fast shaft in hollow slow shaft with ends projecting from gear box to take driving pulleys

摘要

The variable speed circular saw uses a co-axial slow (11) and fast (12) drive shafts to mount slow (7a) and fast (7b) blades. The fast shaft is mounted inside the slow shaft which is thus of a hollow construction and pillow blocks (19,20) maintain the relationship of the two shafts whilst permitting relative rotation. Drive from a motor (38) is transmitted to the fast shaft by an endless belt (35) and stepped (36,32) mounted on the frame (5), a third pulley (42) being used to transmit drive to the slow shaft via a gear train (46). The blades (7) and the fast shaft drive pulley (32) are mounted on opposite ends of the fast shaft with the gear train mounted in between, and the assembly may be incorporated in a cellular box section (5) cantilevered from a post. A projecting end of the compound shaft accepts the two alternative blade types.